Field
Exemplary embodiments of the present invention relate to a method and apparatus for controlling a motor driven power steering system, and more particularly, to a method and apparatus for controlling a motor driven power steering system, which reduces the amount of impact due to collision between a stopper of a rack-bar and an inner ball joint (IBJ) socket (housing) of a gear box.
Discussion of the Background
A hydraulic power steering system that forms a hydraulic pressure in a hydraulic pump and assists the assistive steering force, and a motor driven power steering system (hereinafter, referred to as “MDPS”) assisting the assistive steering force using a driving torque of an electric motor have been used as an auxiliary power steering system for reducing the assistive steering force of a driver at the time of steering a vehicle.
The MDPS provides an improved steering performance and sense of steering compared to the hydraulic power steering system because the electric motor of the MDPS is automatically controlled according to a running condition of the vehicle and the MDPS performs a function to assist the assistive steering force according to a driver's steering wheel operation.
However, in case of an MDPS of the related art, when a driver performs a steering operation in a full turn to the left or right maximum value, a stopper of the rack-bar linked to a steering shaft, and an IBJ socket (housing) of a gear box may be in contact with each other. This contact may cause noise and vibration of the vehicle itself, give an unpleasant feeling to the driver, and shorten the life span of the vehicle due to the mechanical damage.
The related art of the present invention is disclosed in Korean Patent Registration No. 10-0247334 registered on Dec. 10, 1999 and entitled “Electric power-assisted steering”.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.